[Ksplice][Ubuntu-20.04-Updates] New Ksplice updates for Ubuntu 20.04 Focal (USN-4750-1)

[Oracle Ksplice]

Synopsis: USN-4750-1 can now be patched using Ksplice
CVEs: CVE-2020-25669 CVE-2020-27815 CVE-2020-27830 CVE-2020-28588 CVE-2020-28941 CVE-2020-29372 CVE-2020-29568 CVE-2020-29569 CVE-2020-29660 CVE-2020-29661 CVE-2021-20177

Systems running Ubuntu 20.04 Focal can now use Ksplice to patch
against the latest Ubuntu Security Notice, USN-4750-1.

INSTALLING THE UPDATES

We recommend that all users of Ksplice Uptrack running Ubuntu 20.04
Focal install these updates.

On systems that have "autoinstall = yes" in /etc/uptrack/uptrack.conf,
these updates will be installed automatically and you do not need to
take any action.

Alternatively, you can install these updates by running:

# /usr/sbin/uptrack-upgrade -y


DESCRIPTION

* CVE-2020-29569: Use-after-free when disconnecting Xen block devices.

A logic error when disconnecting Xen block devices may cause a use-after-free.
A rouge guest instance may be able to use this to cause a Denial-of-Service
on dom0.


* CVE-2020-29661: Use-after-free in ioctls of TTY subsystem.

A locking flaw in ioctls of TTY subsystem could lead to a use-after-free.
A local user could use this flaw to cause execution of arbitrary code or
a denial-of-service.


* CVE-2020-28941: Denial-of-service in Speakup Screen Reader.

A invalid memory release in Speakup Screen Reader driver when using
the tty line discipline multiple times could lead to the system crash.
A local user could use this flaw for a denial-of-service.


* CVE-2020-29372: Denial-of-service in Memory Management subsystem due to a race condition.

A race condition in Memory Management subsystem could result in loss
of availability. A local user could use this flaw to cause
a denial-of-service.


* CVE-2020-28588: Information disclosure due to syscall registers misuse.

Due to a failure to correctly cast the syscall registers to 64-bit
values, sensitive kernel information can be disclosed to userspace.
A local attacker could use this flaw to facilitate a further attack
on the kernel.


* CVE-2020-29660: Use-after-free in TTY subsystem due to locking inconsistency.

A locking inconsistency in TTY subsystem could lead to a use-after-free.
A local user could use this flaw to cause execution of arbitrary code or
a denial-of-service.


* CVE-2020-25669: Use-after-free in Sun Type 4 and Type 5 keyboard driver.

A logic error in Sun Type 4 and Type 5 keyboard driver could lead to a
use-after-free. A local attacker could use this flaw to cause a
denial-of- service.


* CVE-2020-27830: NULL-pointer dereference in Speakup line discipline.

THe driver for the Speakup Screen Reader exposes a line discipline to
userspace. A bug in the driver fails to account for a NULL
spk_ttyio_synth pointer, resulting in a potential denial-of-service if a
malicious user accesses the discipline.


* Note: Oracle will not be providing a rebootless update for CVE-2020-29568.

Oracle has determined that patching this vulnerability live on a running system
would not be safe and is recommending to reboot the vulnerable hosts.


* CVE-2021-20177: Malicious netfilter rule causes denial-of-service.

Invalid string comparisons on packet data when filtering network traffic
could result in a kernel panic. A malicious user with CAP_NET_ADMIN
might exploit this to cause a denial-of-service.


* Oracle has determined that CVE-2020-27815 is not applicable.

Oracle has determined that CVE-2020-27815 is not applicable and corrects a
false-positive linter warning.  Applying the patch has no resulting
changes in the generated object files.

SUPPORT

Ksplice support is available at ksplice-support_ww at oracle.com.